Grommets are often used to provide a seal between two substrates, e.g., between a pipe and a wall through which the pipe passes. Grommets are potentially difficult to place, as they may be either too tight to move easily along a substrate or, conversely, too loose to provide a water-tight seal between the two substrates. Thus, the use of grommets frequently results in a seal that is not water-tight; leaking of a liquid such as water around a joint between the two substrates can lead to undesirable performance issues and aesthetic problems, for instance visible rusting of a metal substrate. Additional sealing such as a one-part polyurethane sealant applied around the grommets has been one method of providing a water-tight seal, however, this is labor intensive, unsightly, and sometimes still allows liquid to leak around the joint between the two substrates.